Resumen

Dehydration curves in broccoli (Brassica oleraceae L var. Italica Plenk) and cauliflower (Brassica oleraceae L var. Botrytis L). Rev. Fac. Agron. [online]. 2003, vol.20, n.3, pp.306-319. ISSN 0378-7818.

Broccoli is a crop that has an advantageous nutritional composition with respect to proteins, fiber and ash. Cauliflower is a fiber source rich in pectic polysaccharides. When the above mentioned vegetables are dehydrated, their fiber content increases significantly which explains the importance of applying this kind of technology. For the purpose of determining the drying processes in these vegetables, the drying curves at several dry bulb temperature (60, 70 and 80°C) were constructed, using a tray (cabinet) dryer. The moisture in fresh broccoli and cauliflower was 92,11 and 92,2%, respectively. The lowest equilibrium moisture content were 4,3% and 5,4 % in flours obtained from broccoli and cauliflower at 80°C, and were equal to moisture reduction of 85 and 86%, respectively. The results indicate that when the drying temperature is higher, the moisture decrease in the solid is greater; the drying rate in the pre-critical period is greater and the drying time is shorter. The constant-rate zone in both vegetables was clear at 60 and 70°C and not at 80°C. The equilibrium humidity level was reached after two hours of drying, with the exception of broccoli dehydrated at 60°C, in which case it was reached at the third hour.

Palabras clave : Dehydration; broccoli; cauliflower; preservation.